Working in cold weather

Some workers are required to work outdoors in cold weather for extended periods, for example, construction workers, garbage collectors, police officers and emergency workers, like firefighters, and many others. These workers are inevitably more prone to cold stress.

Figure 1: Emergency worker working in rain

Cold stress occurs by driving down the skin temperature followed by the core body temperature. This may lead to serious health problems and can cause tissue damage and even death in some situations.

The most frequent cold induced illnesses or injuries include:

Hypothermia

Frostbite

Trench Foot

Hypothermia:

Hypothermia is a condition that occurs when your body loses heat faster than it can produce heat, causing a dangerously low body temperature. Normal body temperature is around 37 °C. Hypothermia occurs when your body temperature falls below 35 °C, for example when a person becomes drenched from rain or submersion in cold weather.

Frostbite:

It is an injury to the body that is caused by freezing of the skin and underlying tissues. The lower the temperature, the quicker the frostbite will occur. Frostbite typically affects the extremities, particularly the feet and hands. The symptoms are reddened skin with grey to white patches, numbness and blisters can occur in affected areas. In severe cases, amputation may be required.

Trench foot or Immersion foot:

Trench foot is a painful condition of the feet caused by long immersion in cold water or mud and is marked by blackening and death of surface tissue. It can occur at temperatures up to 15°C if the feet are constantly wet. Non-freezing injury happens since wet feet lose heat 25-times quicker than dry feet. To avoid heat loss, the body constricts the blood vessels to decrease circulation in the feet. Consequently, the skin tissues can die due to a lack of oxygen supply and nutrients and due to the accumulation of toxic products. The symptoms of trench foot include redness of the skin, swelling, numbness and blisters.

Precautions:

If you work outside, you may be at risk of exposure to extreme cold. Your workplace must have measures in place manage the risks to your health and safety cause by exposure to cold weather, including:

providing heating, for example cab heaters

providing protection, such as a hut or the cabin of a vehicle

providing warm and waterproof clothing including eye and face protection, head protection and gloves.

enabling workers who are not used to working in cold conditions to acclimatise.Eliminating or reducing exposure to cold is the best protection.